Grinding machine



Feb. 12, 1929. 1,701,669

c. c. FAVRE v GRINDING MACHINE Filed Oct. 12, 1925 George CIFZwra Hot my Patented Folio; 12, 1929.

entree srerss emsnrosrics.

GEORGE CHARLES FAVRE, 0F SOUTHBRIDG-E. MASSACHUSETTS, ASSIGNOR T0 AMERI- CAN OPTICAL CGMPANY. OF SGUTHBRIDGE, MASSACHUSETTS, A VOLUNTARY ASSO- CIATION 0F IiIASSACl-IUSETTS.

Gnrnnino MACHINE.

App ication filed October 12, 1925. Serial in. 82,033.

This invention relates to new and useful improvements in grinding machines and has more particular reference to a grinding mach'ne employed for beveling the edges of ophthalmic lenses. i V

The primary object of the present invention is to provide a grinding machine of the character stated provided. with a new and novel mounting for grinding; sh res. 7

Another importantobject of the invention is to provide such a stone mounting; whereby the grinding stone will be permitted to adapt itself to lenses oi various curwitures. 7

Another object is to provide such a stone mounting wherein the pressure created hv the various surface shapes 0t lenses will tend to oscillate the stone to conform with the i1 regularity of the periphery or lens hem ground.

Another object is to provide such a stone mounting having positive means in the mounting thereot whereby to create in response to the pressure ofthe lensf due to its surface shape an oscillating movement to compensate for the irregularity riphery of the lens.

A "further object is to provide such a mounting of the character stated Which is com paratively simple and inexpensive in its construction yet strong and durable and well adapted for the purposes for which it is de-- signed.

"With these and other novel feature the invention resides in the 'pzn'ticular construetior combinationnnd arrangement of ports to be more fully hereinafter descril: Ed illustrated in the accompanying drawing, particularly pointed out in the appended claims; I

In the drawings forming a part of this application and in which is disclosed a preferred embodiment of the present invention Figure 1 is a side elevation of a stone mounting constructed in accordance with the present invention.

of the pci in, 2 is diagrammatic plan view of a grindingmachine showing the arrangement and V Figure at is a framentary sectional view showing the relationship of the lens with the grinding stone.

In the drawings, wherein like characters ot reference denote corresponding parts throughout the several views, there is dis closed a grinding machine including a shaft 10 mounted in the journals'or bearings 11', and driven by the belt and pulley i2'and 13.

Mounted on the drive shaft 10, and rotatable therewith a. hub designated as a Whole by: the numeral id. and comprising; a pair or collars l5 and-l6 held together by a plurality of fastening bolts 1'?" and being fixed or secured on the shaft-ray a set screw or the like 18. The bolts 11 are positionedatequelly spaced distances around said collars 15 and 16 the i ijecent t has of which are' iiartiallfv cut away or recessed to form an annular groove 19. i

A grinding stone encircling the said col lars has the rings 21 and 22 PUSlLlOllGCi at op positesides thereof, and adjacent its inner edge, these rings being clamped onto the stone by means 01" a plurality oibolts ar ranged equally spaced "distances around flexible membe s El i-i which radiate from the hub 14-, theinne end of each or said members being plvotailv I aired to one Gil: the first inn ing bolts 17., While the opposite or outer end thereof is likewise pivotallv secured to the bolt 22) directly in advance of'lhe bolt 1'7, to which the inner end is securechthe term in advance of meaning in the'direction of retation otthe shaft 10.

Positioned forwardly o the shaft 10 is a Li clanu. .ihaits 9 to be receive 0 W ..in the sha 50 2 nine; stone l0 said s arts?!) and"; driven'by the belt and arena 31 respectively ormer 825 the parted to the finished lens. This former is held in contact with the former shoe 33 c p r is it size and shape of which are adapted to be n'nthrough the medium of suitable spring means ,34, which also serves to retain the lens within {the groove of the grinding ston l The principle and operation of the invention is as follows: when it is desired to bevel the edges of a lens, the said lens is lirst clamped between the shafts and 2t and 's held within the groove of the grinding stone, after which the said lens, together with the stone, is caused to be rotated. As the lens and stone rotate, the pressure upon the stone will be varied according to the surlace shape of the lens, with the result that'the stone will be oscillated to ontorm to the curvature thereof.

As an example, let us assume that it is desired to bevel the edge 0t an elliptical lei'is having a curved surface, such as shown in Figure 4. When this lens is rotated and engages with the stone at the point A, it will have a difference in position lon 'itudinally than when it engages the stone at the point B. The lens havin the curved surface will have a displacement longitudinally between the point A and the point B when the distance from the center to the point is di crent than the distance from the center to the point A. This is true of all curved surfaces including spherical and toric surfaces, that is, where the curved surface has the same curvature in the two major meridians or where it has a different curvature in the two major meridians. Of course, this displacement is only true for a spherical lens where the shape of the lens is other than round, but in the case of a toric lens it is true even for a round 1 As the lens is rotated in the groove 30 of the grindstone there is a pressure set up tending to displace the edge of the grindstone in a direction parallel with the thereof. This pressure will cause the resilient members as to belly or flex so that the grindstone annulus 20 is displaced in a direction parallel with the shalt oi the grindstone which keeps the bevel oi the lens centrally dis' posed with spect to theedge of the lens,

From the above it will be readily [iPPl'Q- elated that there has been provideo a structure which will. accomplish all of the objects and perform all of the functions claimed. It is also to be understood that various modifications may be found desirable when producing this mounting comn ercially, and the rightis hereby reserved to maize any such changes as properly fall within the scope of the appended claims without from or exceeding the spirit of the ini What is claimed is:

1. A. grindstone mounting comprising a hub, an annular ring grindstone and a pinrality of flexible fiat blade bar members each having one end connected to the hub and the other end connected to the annular ring, the material of said flexible blade bar members being disposed so that they are flexible in a direction normal to the plane of the grindstone.

2. A Igrindstone mounting comprising a hub, an annular ring grindstone and a plurality oi flexible m'en'ibers each having one end pivoted to the hub and the other end pivot'ed to the annular rin the material of said flexible members being disposed so that they are flexible in a direction normal to the plane of the grindstone.

' 3. it grindstone mounting comprising a 'rindstone shaft, a hub on the grindstone aft having annular groove thercaround, an annular ring grindstone having a grooved ring on the inside of the annulus and a plurality of flexible members each having one end secured in the groove in the hub and the other end secured in the groove on the inside of the annular grindstone, the material of said flexible members being disposed so that they are flexible in a direction normal to the plane of the grindstone.

l. A grindston'e mounting comprising a grindstone shaft, a hub on the ,grindstone shaft having an annular groove therearound, an annular ring grindstone, an annular grooved member on the inside of the grindstone annulus and a plurality of flexible members, each having one end pivoted in the groove of the hub and the other end pivoted in the, groove or" the grooved member on the inside of the annular grindstone, the material of said flexible members being disposed so they are flexible in a direction normal to the plane of the grindstone.

5. A grindstone mounting comprising a grindstone shaft, a hub on the grindstone shaft, an annular ring grindstone and a plurality of flexible blade bar members connected to the hub and to the annular ring' grindstone that will bulge orilex in a direction normal to the plane of the grindstone when pressure is applied. to the edge of the grindstone to displace thecdge of the grindstoue in a direction parallel to the axis of the grindstone shaft.

6. A grindstone mounting comprising a grindstone shaft, a hub on the grindstone shaft, an annular ring grindstone and a plurality of flexible blade bar members having pivotal connections to the hub and to the annular ring grindstone so that they will bulge or flex in a direction normal to the plane of the grindstone when pressure is applied on the edge'of the grindstone whereby the edge of t e grindstone will be displaced in a direction parallel with the axis of the grindstone shaft; p 7 V i GEORGE CHARLES FAVRE. 

